Di-piperidinium-crosslinked poly(fluorenyl-co-terphenyl piperidinium)s for high-performance alkaline exchange membrane fuel cells

Modern anion exchange membrane (AEM) fuel cells (AEMFCs) call for highly conductive, durable, and mechanically tough AEMs and ionomers. Here, we report a series of scalable di-piperidinium-crosslinked poly(fluorenyl-co-terphenyl piperidinium) (x-PFTP-DP-Cn) copolymers with high ion exchange capacity (IEC) and tunable crosslinking alkyl spacers (Cn, n = 5 or 10) to reinforce the mechanical strength and optimize the electrochemical performance of poly(aryl piperidinium)-based AEMFCs. Specifically, durable x-PFTP-DP AEMs display high ion conductivity (HCO3- >90 mS cm(-1) and OH- >180 mS cm(-1) at 90 degrees C) and excellent mechanical strength (tensile strength similar to 90 MPa, elongation at break similar to 35%). Importantly, the x-PFTP-DP-based AEMFCs achieve outstanding peak power densities of 2.50 W cm(-2) in H-2-O-2 and similar to 1.41 W cm(-2) in H-2-air at 80 degrees C. Moreover, the present AEMFCs can run stably under 0.2 A cm(-2) and 0.6 A cm(-2) current densities at 70 degrees C for 265 h and 110 h, respectively, with low voltage decay rate of similar to 50 mu V h(-1).

Automated summary

We report a scalable polymer with high ion exchange capacity for the development of anion exchange membrane fuel cells. The fuel cells exhibit excellent electrochemical performance, mechanical strength, and stability under different conditions, with low voltage decay rate.